The present invention relates to piezo-electric level sensors that detect the level of oil in the crankcase of an internal combustion engine.
A conventional piezo-electric sensor that detects the presence of oil by means of a transducer mounted in a tubular member oriented in the manner depicted in FIGS. 2 and 4A is not reliable because oil may cling to the horizontal surface to which the sensing element is bonded. Even when such a sensor is mounted obliquely as shown in FIGS. 2A and 8A, oil may adhere to the exterior of the surface on which the sensing element is bonded and give erroneous indications of the oil level.
Where the remote sensing of oil level in a crankcase can activate an alarm or even shut down the engine, the reliability of the sensor should be high. In addition, if the sensor detects oil on the end of the sensor but the oil level is actually below the end of the sensor, serious engine damage can occur without a warning from the sensor.
Therefore, it is the principle object of the present invention to provide a sensor that detects the level of engine oil for an internal combustion engine that is not susceptible to false readings caused by oil adherent to the end of the sensor.
A further object of the invention is to provide a sensor that is oriented to drain oil that is splashed upon it by operation of the engine.
These and other objects of the invention can be accomplished by practice of the invention as herein disclosed.